Ecology Practice Problems

Ecology Practice Problems
Multiple Choice Identify the choice that best answers the question.
____ 1. A community is made up of
a. potentially interacting populations of different kinds of organisms.
b. one species of organism living in one particular environment on Earth.
c. living organisms and their nonliving environment.
d. several ecosystems on one continent.
e. the factors that constitute an organism's niche.
____ 2. In terms of global air circulation, the tropics are a region where air
a. descends and warms, dropping rain.
b. descends and warms, creating an arid belt.
c. rises and warms, creating an arid belt.
d. rises and cools, creating an arid belt.
e. rises and cools, dropping rain.
____ 3. Most of the world's deserts are located at latitudes where
a. hot, dry air moving toward the equator rises.
b. hot, dry air moving toward the poles rises.
c. hot, dry air moving toward the poles descends.
d. cold, dry air moving toward the poles descends
e. cold, dry air moving toward the equator descends.
____ 4. Under the conditions known as El Nino, the mineral nutrient content of the seawater off the coast of Peru
declines to very low levels. What effect will this likely have on marine life in the area?
a. The lower the levels of minerals, the less polluted the water; hence, most populations will increase.
b. It will result in toxic red tides, which will reduce the populations of many species.
c. It will reduce the abundance of phytoplankton and, consequently, the abundance of other organisms.
d. It will increase the productivity of phytoplankton and, therefore, the productivity of other organisms
by decreasing salinity.
e. It will increase the productivity of phytoplankton and, therefore, the productivity of other organisms
by allowing sunlight to penetrate deeper into the ocean.
____ 5. Which of the following choices does not correctly pair a biome with some of its characteristics?
a. temperate forest cold winters, moderate to high rainfall, predominantly dicot vegetation
b. temperate grassland cool to cold winters, dry summers
c. chaparral mild, rainy winters; long, hot, dry summers
d. savanna long, cold winters, vegetation dominated by conifers
e. tundra very cold winters; only the upper layer of the soil thaws during summer
____ 6. In which of the following biomes would you expect to find the highest abundance of large grazing mammals?
a. tropical rain forest c. temperate grassland e. temperate forest
b. chaparral d. desert
____ 7. If an ecosystem has a carrying capacity of 1,000 individuals for a given species, and 2,000 individuals of that
species are present, we can predict that the population
a. size is at equilibrium. d. will show a uniform dispersion pattern.
b. size will decrease. e. size will slowly increase.
c. will show a clumped dispersion pattern.
____ 8. Consider a stable frog population living at carrying capacity in a pond. If an average female produces 6,000
eggs during her lifetime and an average of 300 tadpoles hatch from these eggs, how many of these tadpoles
will, on average, survive to reproduce?
a. 0 c. 10 to 20 e. more than 100
b. 2 d. 100
____ 9. A Type I survivorship curve is the result of which of the following life-history traits?
a. Parents provide extended care for their young.
b. Large numbers of offspring are produced.
c. Infant mortality is much greater than adult mortality.
d. Death rates are constant over the life span.
e. Most individuals have short life spans.
____ 10. The death by bubonic plague of about one-third of Europe's population during the fourteenth century is a
good example of
a. abiotic factors limiting population size. d. a density-independent effect.
b. a density-dependent effect. e. carrying capacity.
c. a time lag.
____ 11. In the logistic growth model, as population size increases,
a. birth rates remain constant and the death rates increase.
b. birth rates decline but the death rates remain steady.
c. birth and death rates increase.
d. birth and death rates remain steady.
e. birth rates decline and/or death rates increase.
____ 12. Which one of the following organisms best illustrates K-selection?
a. the production of thousands of eggs every spring by frogs
b. mice that produce three litters of 10-15 babies in the course of a summer
c. a polar bear producing one or two cubs every three years
d. a species of weed that quickly spreads into a region of cleared trees
e. All of the choices are examples of K-selection.
____ 13. An adult human jumps into a raging river to try to save a child who is drowning and is unrelated to the
adult. This is an example of
a. ingrained behavior. c. imprinted behavior. e. dominant behavior.
b. reciprocal altruism. d. kin selection.
____ 14. In an ecosystem, you would most expect to find interspecific competition between
a. males and females of a species in which both sexes occupy the same niche.
b. populations of two species that occupy the same niche.
c. males of a species during the breeding season.
d. a prey species and its predator.
e. two wasp species that mimic each other's appearance.
____ 15. Which of the following is an example of Batesian mimicry?
a. the resemblance of a harmless fly to a bee
b. the resemblance of the walking-stick insect (a kind of mantis) to the twigs of a tree
c. the resemblance of an African sunbird to a Central American hummingbird that occupies a similar
niche
d. the resemblance of the western meadowlark to the eastern meadowlark
e. the similar appearance and black-and-gold coloration of many wasps
____ 16. The relationship between a cow and the cellulose-digesting bacteria in the rumen of its gut would best be
described as
a. predation. c. mutualism. e. interspecific competition.
b. parasitism. d. commensalism.
____ 17. During ecological succession, the species composition of a plant community generally
a. changes from a diverse community in which many plants are common to one in which a few species
are numerically dominant.
b. simplifies until most of the plants originally present have disappeared.
c. remains stable as long as major environmental factors (climate, human interference) remain constant.
d. changes gradually because each species responds differently to the changing environment.
e. changes until climax forest is established and a single species remains.
____ 18. When a nipple is placed in a newborn baby's mouth, the infant will immediately begin to suckle. This is an
example of
a. habituation. c. classical conditioning. e. imitation.
b. imprinted behavior. d. innate behavior.
____ 19. In a particular songbird species, you are told, the song of males has an innate component but is also largely
learned: Nestling males imprint on their father's song, and then sing it themselves when they reach sexual
maturity. Which of the following observations would lead you to doubt this information?
a. A male chick reared in isolation grows up to sing a rudimentary version of his species' song.
b. A male chick reared in isolation and introduced as a subadult into an aviary containing normal
males of his species sings his species' song.
c. A male chick who is reared in isolation but hears tape recordings of his species' song grows up to
sing normally.
d. A male chick who is reared in isolation but hears tape recordings of a different species' song grows
up to sing that species' song.
e. A male chick fostered in the nest of a different species grows up to sing the song of its foster species.
____ 20. A grayling butterfly will normally fly toward the sun. This is an example of
a. kinesis. c. phototropism. e. instinct.
b. migration. d. taxis.
____ 21. Squirrels on a bird feeder seem to be able to figure out how to steal seeds no matter what people do.
Yesterday, Jeremy hung out a new bird feeder design, and sure enough, by the end of the day the squirrels
found a way to get to the seeds. The squirrels most likely figured out how to get the seeds through
a. trial-and-error learning. d. imprinting.
b. habituation. e. spatial learning.
c. the use of cognitive maps.
____ 22. The baby bobcats watched as their mother stalked a rabbit and pounced, catching dinner that was shared by
all. The next day, two of the young bobcats were seen stalking a field mouse, which quickly escaped from the
inexperienced hunters. The young bobcats were learning how to hunt by the process of
a. social learning. c. habituation. e. cognitive map learning.
b. imprinting. d. associative learning.
____ 23. Which of the following would be an example of agonistic behavior?
a. A dog raises its hackles, bares its teeth, and stands high to appear threatening.
b. A honeybee does a waggle dance to indicate the direction of food.
c. A male ruffed grouse spreads its tail and beats its wings to attract a female.
d. Fireflies flash in a species-specific pattern.
e. Ants mark their trails by releasing pheromones.
____ 24. In an average ecosystem, about how much energy is present in the organisms at a given trophic level
compared to the organisms at the next higher trophic level?
a. a tenth as much
b. half as much
c. twice as much
d. ten times as much
e. It is impossible to say without knowing which trophic levels are involved.
____ 25. In a hypothetical food chain consisting of grass, grasshoppers, sparrows, and hawks, the grasshoppers are
a. primary consumers. c. secondary consumers. e. detritivores.
b. primary producers. d. secondary producers.
____ 26. Which of the following substances is not cycled between organic matter and abiotic reservoirs?
a. water
b. carbon
c. nitrogen
d. phosphorus
e. All of the choices are cycled between biotic and abiotic reservoirs.
____ 27. Which of the following is not true of the nitrogen cycle?
a. It requires different types of bacteria.
b. Nitrogen gas is converted to nitrates in plant leaves.
c. Nitrogen is cycled through living organisms.
d. When plants and animals die, their nitrogen is recycled.
e. Nitrogen is a component of all proteins.
____ 28. According to the competitive exclusion principle, two species cannot continue to occupy the same
a. environmental habitat. c. territory. e. biome.
b. ecological niche. d. range.
____ 29. For a given area and time period, the amount of solar energy converted to chemical energy is called
a. primary succession. d. secondary production.
b. secondary succession. e. primary photosynthesis.
c. primary production.
____ 30. During ecological succession, the species composition of a plant community generally
a. changes from a diverse community in which many plants are common to one in which a
few species are numerically dominant.
b. simplifies until most of the plants originally present have disappeared.
c. remains stable as long as major environmental factors (climate, human interference)
remain constant.
d. changes gradually because each species responds differently to the changing environment.
e. changes until climax forest is established and a single species remains.
____ 31. The greatest crisis ever faced by humans is probably
a. the ozone hole. d. air and water pollution.
b. global warming. e. human population growth.
c. hazardous waste disposal.
____ 32. Why is the runoff from fertilized agricultural fields, even if free of pesticides, often harmful to the ecosystems
of temperate lakes?
a. Fertilizer compounds are toxic to fish.
b. The runoff causes a surface algal bloom, which reduces the lake's oxygen by cutting off
the sunlight and fouling the water with dead organic matter.
c. The runoff raises the levels of inorganic nutrients in the surface waters to levels that are
toxic for algae and other lake organisms.
d. Runoff water pools at the lake's bottom, where the fertilizer compounds react with
materials in the sediment to form toxic substances.
e. The runoff is acid, and acidification kills key lake organisms.
Ecology Practice Problems
Answer Section
1.A 11.E 21.A 31.E
2.E 12.C 22.A 32.B
3.D 13.B 23.A
4.C 14.B 24.D
5.D 15.A 25.A
6.C 16.C 26.E
7.B 17.D 27.B
8.B 18.D 28.B
9.A 19.B 29.C
10.B 20.D 30.D